We discovered that phenylbutyrate, prevents both in vitro and in vivo the inactivation by phosphorylation of the branched chain ketoacid dehydrogenase complex (BCKDC) and pyruvate dehydrogenase complex (PDHC). We show that phenylbutyrate is effective for treatment of maple syrup urine disease (MSUD) due to deficiency of branched chain ketoacid dehydrogenase complex (BCKDC), and has potential for t ...